A network may include multiple domains, such as subscriber, provider, and operator domains. Maintenance packets, such as Operations, Administration, and Maintenance (OAM) packets, are used to maintain the operational status of the network. In certain situations, a maintenance point should be prevented from processing and possibly responding to a maintenance packet that is from a non-trusted source, has been altered in transit, or has been copied and replayed. Known techniques for achieving this, however, are not satisfactory in certain situations.